Stepper motor testing

U

Uriah

Guest
Is there a way I can test a stepper motor on my bench without the
driver? Does anyone make a stepper motor test device?
Thanks
Russ
 
Uriah wrote:
Is there a way I can test a stepper motor on my bench without the
driver? Does anyone make a stepper motor test device?
Thanks
Russ
If you take a 4 bit shift register, clock one bit around in it,
connect the 3rd bit to the input,and attatch 3 bits with a 1-3
ampere darlington transistor to the 3 coils, and the common to
something like 5 or 12 volt supply, shift the register with
something like 5 hz(or use a pushbutton),
you have a nice tester.
Swap two coil wires to reverse direction.
Oh and put 1 amp diodes across the coils to keep your transistors
from breaking down.
 
On 2009-02-10, Uriah <uriahsky@hotmail.com> wrote:
Is there a way I can test a stepper motor on my bench without the
driver?
what tests do you want to do?

Does anyone make a stepper motor test device?
I've used aligator clips in the past.
 
On Feb 9, 9:01 pm, Uriah <uriah...@hotmail.com> wrote:
Is there a way I can test  a stepper motor on my bench without the
driver?  Does anyone make a stepper motor test device?
Thanks
Russ
Hi, Russ. Use a few switches and manually go through the steps. Does
that make sense?

Cheers
Chris
 
"Uriah" <uriahsky@hotmail.com> wrote in message
news:9a511395-082e-41b7-8f11-1069994e2b3f@u18g2000pro.googlegroups.com...
Is there a way I can test a stepper motor on my bench without the
driver? Does anyone make a stepper motor test device?
Thanks
Russ
Use a meter to determine each coil resistance. They should be close.
Then tap 5 volts across once coil, feel the shaft, it should bump once for
each tap.
The other coil should do the same thing.
 
Uriah wrote:

Is there a way I can test a stepper motor on my bench without the
driver? Does anyone make a stepper motor test device?
Thanks
Russ
sure, connect some AC to it. it'll move...

http://webpages.charter.net/jamie_5"
 
On Feb 10, 3:10 am, Chris <cfoley1...@yahoo.com> wrote:
On Feb 9, 9:01 pm, Uriah <uriah...@hotmail.com> wrote:

Is there a way I can test  a stepper motor on my bench without the
driver?  Does anyone make a stepper motor test device?
Thanks
Russ

Hi, Russ.  Use a few switches and manually go through the steps.  Does
that make sense?

Cheers
Chris
This sounds easy but is it through. Sometimes I find a stepper motor
in the equipment that just kind of vibrates back and forth. Do you
think the switches would catch this kind of thing?
 
On Feb 10, 1:52 pm, "bw" <bweg...@hotmail.com> wrote:
"Uriah" <uriah...@hotmail.com> wrote in message

news:9a511395-082e-41b7-8f11-1069994e2b3f@u18g2000pro.googlegroups.com...

Is there a way I can test  a stepper motor on my bench without the
driver?  Does anyone make a stepper motor test device?
Thanks
Russ

Use a meter to determine each coil resistance. They should be close.
Then tap 5 volts across once coil, feel the shaft, it should bump once for
each tap.
The other coil should do the same thing.
I was checking a few and found one coil with the resistance down from
5.3 ohms to 2.6 ohms. Is this enough to cause a problem? If one coil
is off by a few ohms this could cause the thing not to spin correctly
I would think. Because of the costs of the motor, driver pcb and down
time I hope I can find something that can tell me almost for sure that
it is good or bad. I guess I will have to experiment a little.
Thank you,
Russ
 
On Feb 10, 5:00 pm, Jamie
<jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:
Uriah wrote:
Is there a way I can test  a stepper motor on my bench without the
driver?  Does anyone make a stepper motor test device?
Thanks
Russ

  sure, connect some AC to it. it'll move...

http://webpages.charter.net/jamie_5"
Are you sure about that...
 
On Feb 9, 9:08 pm, Sjouke Burry <burrynulnulf...@ppllaanneett.nnll>
wrote:
Uriah wrote:
Is there a way I can test  a stepper motor on my bench without the
driver?  Does anyone make a stepper motor test device?
Thanks
Russ

If you take a 4 bit shift register, clock one bit around in it,
connect the 3rd bit to the input,and attatch 3 bits with a 1-3
ampere darlington transistor to the 3 coils, and the common to
something like 5 or 12 volt supply, shift the register with
something like 5 hz(or use a pushbutton),
you have a nice tester.
Swap two coil wires to reverse direction.
Oh and put 1 amp diodes across the coils to keep your transistors
from breaking down.
Thanks I guess this is the answer. You don't think there will be a
problem using different motors with different resistance or number of
coils?
 
On Feb 10, 2:34 am, Jasen Betts <ja...@xnet.co.nz> wrote:
On 2009-02-10, Uriah <uriah...@hotmail.com> wrote:

Is there a way I can test  a stepper motor on my bench without the
driver?

what tests do you want to do?

I just want to see if it works. When I find them on the equipment I
sometimes have to guess if it is the motor or the driver pcb. Both are
expensive so I just want to take the motor and test it with a
something and watch it spin around.
 
Uriah wrote:
On Feb 10, 5:00 pm, Jamie
jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:

Uriah wrote:

Is there a way I can test a stepper motor on my bench without the
driver? Does anyone make a stepper motor test device?
Thanks
Russ

sure, connect some AC to it. it'll move...

http://webpages.charter.net/jamie_5"


Are you sure about that...
Yes, I'm sure about that.

The amount of AC depends on the motor voltage rating.



http://webpages.charter.net/jamie_5"
 
On Wed, 11 Feb 2009 15:34:27 -0800 (PST), Uriah <uriahsky@hotmail.com>
wrote:

On Feb 10, 1:52=A0pm, "bw" <bweg...@hotmail.com> wrote:
"Uriah" <uriah...@hotmail.com> wrote in message

news:9a511395-082e-41b7-8f11-1069994e2b3f@u18g2000pro.googlegroups.com...

Is there a way I can test =A0a stepper motor on my bench without the
driver? =A0Does anyone make a stepper motor test device?
Thanks
Russ

Use a meter to determine each coil resistance. They should be close.
Then tap 5 volts across once coil, feel the shaft, it should bump once fo=
r
each tap.
The other coil should do the same thing.

I was checking a few and found one coil with the resistance down from
5.3 ohms to 2.6 ohms. Is this enough to cause a problem? If one coil
is off by a few ohms this could cause the thing not to spin correctly
I would think. Because of the costs of the motor, driver pcb and down
time I hope I can find something that can tell me almost for sure that
it is good or bad. I guess I will have to experiment a little.
Thank you,
Russ
Greetings Russ,
Stepper motors, at least the kind you are likely to find, e.g., in a
printer or disc drive, will have 4 coils. If there are 5 wires coming
out of the stepper then the coils will be connected in pairs giving
you in effect two center tapped coils. So, if you measure from the
center tap to one end of the coil the resistance will be 1/2 of what
you would get if you measured the resistance across the ends. Which is
just what you measured. The rotor has teeth on it that line up with
the coils as they are energized. That is why just applying DC power to
any pair of wires won't make the motor spin. The coils must be turned
on and off in sequence to make the thing spin. This is what makes
stepper motors so useful. They are used to position the shaft by
stepping the motor the desired number of steps and no position
feedback is needed. If you can spin the shaft with your fingers then
you can test the motor by applying DC to a pair of wires and feeling
the change in the torque required to spin the shaft manually compared
to when the power is removed. If there is no change then that coil is
bad. Unlikely though to find a bad stepper. As you apply power to
different pairs of wires the motor shaft should step, apply power in
the correct sequence and the shaft will step in one direction instead
of stepping back and forth.
ERS
 
Uriah wrote:
On Feb 9, 9:08 pm, Sjouke Burry <burrynulnulf...@ppllaanneett.nnll
wrote:
Uriah wrote:
Is there a way I can test a stepper motor on my bench without the
driver? Does anyone make a stepper motor test device?
Thanks
Russ
If you take a 4 bit shift register, clock one bit around in it,
connect the 3rd bit to the input,and attatch 3 bits with a 1-3
ampere darlington transistor to the 3 coils, and the common to
something like 5 or 12 volt supply, shift the register with
something like 5 hz(or use a pushbutton),
you have a nice tester.
Swap two coil wires to reverse direction.
Oh and put 1 amp diodes across the coils to keep your transistors
from breaking down.

Thanks I guess this is the answer. You don't think there will be a
problem using different motors with different resistance or number of
coils?
No. Just find the common connection of the coils, and for the number
of coils, make the shift register the same length of bits.
Most are 4 coils, and have a 5 pin connector, but 3 coils is also
possible.
My first message talked about 3 coils.
 
On Feb 9, 7:01 pm, Uriah <uriah...@hotmail.com> wrote:
Is there a way I can test  a stepper motor on my bench without the
driver?  Does anyone make a stepper motor test device?
You need to switch four wires in a phased way; two ways to
do this, are a clocked circuit, and a manual switched driver.

For the clocked circuit, feed an oscillator into two D flip/flops,
D1 (Din input of flip/flop # 1) connected to Q2, and
D2 connected to /Q1 (that's the inverted output of flip/flop 1).
Power is applied from a bench supply through a limit
resistor to the common point, and transistor or MOSFET
switches driven from Q1 and /Q1 drive one coil winding
while switches from Q2 and /Q2 drive the other winding.

And, of course, a four-position make-before-break rotary switch
with two wafers (DP4T) can be connected to do the same thing as
all the clocks and transistors. A 15 degree stepper will
complete one revolution when the switch is cranked through
24 turns. Maybe it'd be easiest to use a cast-iron disk
from an exercise weight set as your knob; spin it up!

Every old moving-ball mouse generates the right phases
for running a stepper, too.
 

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